Cita APA (7a ed.)

Kortmann, B., & Upton, C. (2008). Varieties of English. Mouton de Gruyter.

Cita Chicago Style (17a ed.)

Kortmann, Bernd, y Clive Upton. Varieties of English. Berlin [etc.]: Mouton de Gruyter, 2008.

Cita MLA (9a ed.)

Kortmann, Bernd, y Clive Upton. Varieties of English. Mouton de Gruyter, 2008.